1. Field of the Invention
Devices and methods consistent with the present invention relate to a data storage device, and more particularly, to a data storage device using a magnetic domain wall movement of a magnetic material and a method of operating the data storage device.
2. Description of the Related Art
A minute magnetic region that constitutes a ferromagnetic body is referred to as a magnetic domain. The rotation of electrons in a magnetic domain, that is, the direction of a magnetic moment is identical. The size and magnetization direction of magnetic domain can be appropriately controlled by the shape and size of a magnetic substance and external energy.
A magnetic domain wall is a boundary portion of a magnetic domain having a magnetization direction different from another magnetic domain. The magnetic domain wall can be moved by an external magnetic field or by a current applied to a magnetic substance. That is, a plurality of magnetic domains having a specific magnetization direction can be formed in a magnetic layer having a predetermined width and thickness, and the magnetic domains can be moved using a magnetic field or a current having an appropriate strength.
The principle of the magnetic domain wall movement can be applied to data storage devices. For example, when magnetic domains pass through a read/write head by a magnetic domain wall movement, an operation of reading/writing data is possible without rotating a recording medium. Since data storage devices using a magnetic domain wall movement have a relatively simple structure and a small bit size, every large storage capacity at a terabit-level can be achieved.
However, since such data storage devices are in the first stage of development, several problems should be solved so as to obtain high integration and large capacity. In particular, in data storage device using the magnetic domain wall movement, since reading/writing operations are performed while pushing and pulling the magnetic domain wall, a buffer area is required as a temporary storage. The buffer area reduces the available recording density of a magnetic layer.
Accordingly, in order to realize a small-sized mass storage device using the magnetic domain wall movement, a reduction of the recording density due to the buffer area should be minimized.
In addition, in order to realize a mass storage, a distance between the buffer area and a storage area which is a real data storage should be minimized, and thus a data access time should be reduced.